Switches are under development in the automotive industry for mounting on the steering column of a car or truck, for control of the windshield wipers and the windshield washers from a single control handle.
Typically, the control handle has a rotatable operating knob which can be turned between an off position, and several windshield wiper actuating positions including a low speed position, a high speed position, and an intermittent or delay position at which the windshield wiper operates intermittently but at a variable rate, depending upon the rotational position of the control knob. Also, the control knob can be turned to an operating position, from which position it is spring-biased back to off, so that the windshield wipers only operate when the control knob is positively held in that position.
In addition to this, the control handle may carry an outer sleeve which rotates around the control handle to actuate the windshield washer system. Thus, on the one control handle a large number of different functions are controlled by the same handle. It may also be desired for yet additional functions to be provided to the control handle.
Such a control handle, of course, requires a complex switch to make the necessary connections for accomplishing the functions called for by the various positions of the control handle.
In accordance with this invention, such a switch is improved in several ways. The particular design of this invention makes it possible to eliminate a rotatable carrier and a cover, compared with the corresponding switch of the prior art, without any loss in function. Specifically, means are provided for including a variable resistor circuit for the variable delay action of the windshield wiper, without the need for an extra rotatable carrier and cover.
Additionally, an improved type of rotatable carrier is provided, particularly useful for multiple function switching, in which three or more specific different switching positions can be provided by rotation of the carrier.